Build a debugger for the Haskell agent (Omni/Agent.*) only. Focus on prompt construction + hydration trace, tool calls, and inference events. No pi support for this epic.
Goals:
- Capture prompt build sections + sources + token counts
- Capture hydration stats (memories, bytes/tokens)
- Replay/step through event stream
- Provide CLI to inspect prompt and step events
Out of scope:
- pi/agentd subprocesses
- OpenTelemetry/Jaeger integration